Railway track construction method

ABSTRACT

A method for constructing at least one railway track (V 1,  V 2 ) on a platform ( 5 ), wherein the permanent crosspieces are placed at the substantially permanent site thereof essentially through the use of railway vehicles ( 20, 30, 40 ). Crosspiece deposits are pre-formed on the platform ( 5 ) and along at least one track to be constructed (V 1,  V 2 ) via railway vehicles. The method also includes the placement of rails on the crosspieces. The rails are pushed in front of a placement car for the first track (V 1 ) and are deposited by sliding same out of a rail storage and placement train in a direction to the rear of the train and skewed in relation to the axis of the train for the second track (V 2 ).

The present invention relates to a railway track construction method and a train specially adapted to implement that method. It applies to the construction of a single-track line or a two-track line.

The construction of the new railway track, for example a TGV line, is a very major undertaking implementing specific equipment and a heavy and expensive infrastructure representing a very high cost. It is important to optimize the use of these means to reduce costs.

After constructing the compacted aggregate platform on which the tracks of the line to be built will rest, the state of the art in this area consists of:

-   -   placing a first provisional track made up of provisional panels.         These panels are made in a staging ground and are brought         on-site by a train traveling forward on the track as it is         built; they are made up of rails 18 m long mounted on wooden or         concrete crossbeams and placed on the platform using gantry         cranes mounted on tires or railway beams;     -   placing final continuous welded rails (CWR) along that first         track,     -   establishing a substitution worksite for temporary rails and/or         panels, so as to replace the temporary rails and/or panels with         the permanent material;     -   from the first track thus built, placing the crossbeams of the         second track,     -   still from the first track, placing the final rails of the         second track on the crossbeams,     -   ballasting.

The construction of a two-track line according to this state of the art is therefore done in two different steps that are offset over time. It requires the manufacture of temporary panels on a staging ground, those panels having to be brought to the worksite using a special train.

The logistics for such a worksite are very heavy, since four types of trains must travel on the track under construction:

-   -   the trains that bring the panels,     -   the trains that bring the final crossbeams,     -   the continuous welded rail trains,     -   the ballast trains.

The invention proposes to optimize the method for building a railway track. To that end, it proposes a method for building a railway track on a platform, including the following steps:

-   -   removing at least one rail in the axis of a rail storage and         placement train and in front of it, said train being stopped on         the first already-built portion of said track under         construction, using removal means secured to said train,     -   longitudinally moving at least one rail at least indirectly on         the crossbeams of said track under construction, so as to build         a second portion of said track in the extension of the first         portion.

In the method according to the invention, the train for storing and placing rails progresses on the track under construction. A first portion of the first track has already been built and the train parks on that first portion. This step of the method consists, from storage cars of the train, of removing the two rails in the axis of the storage car and in front of the train, so as to place them in the extension of the rails of the first portion of the first track and form the subsequent portion, or second portion, of the first track. The train is provided with means that will be described later for performing that removal.

One advantage arises from the fact that panels prefabricated at the staging ground are no longer used, and the rails that are placed to build this first track are the final rails. This procures significant savings in terms of labor, since it is no longer necessary to build these panels, in terms of logistics, since it eliminates the train supplying the panels, and footprint, since the staging ground will be smaller.

Advantageously, the crossbeams may have been previously deposited on the platform in their substantially final location in said track under construction.

In the method according to the invention, the final crossbeams are placed in their final location, subject to adjustments, before the rails are placed, which is also a significant advantage of the method.

The step for placing the crossbeams includes the following phases:

-   -   building up stores of crossbeams on the platform using road         vehicles; these vehicles may for example access the platform of         the track under construction using side access roads; the         spacing of these stores and the number of crossbeams deposited         are adapted so that these stores are used later by the         crossbeam-placing vehicles without having to resupply between         two stores;     -   placing two longitudinal layers of ballast on the platform per         road truck;     -   picking up an inventory of crossbeams by a construction vehicle         and depositing that store on a conveyor; the construction         vehicle is for example a mechanical digger provided with an         articulated arm and a spreader; the conveyor is for example         mounted on a road trailer;     -   placing the crossbeams in their final location; this placement         uses a placement vehicle associated with the conveyor, mounted         on several tires and adapted to respect the standard spacing of         60 cm between the crossbeams.

The conveyor and the placement vehicle are hitched to the construction vehicle, which therefore ensures the progression of the placement work.

The advantage of this method is that it only primarily involves road vehicles, i.e., provided with tired wheels. It contributes to eliminating prefabricated panels and trains for conveying those panels.

Advantageously, the step consisting of moving said rail on the crossbeams of the track under construction may include guiding said rail by a front end.

In the step for removing rails designed to make up a second portion of the first track, it is advantageous to guide each rail as it is removed from the storage cars, for example using a construction vehicle equipped with a pivoting arm and over-spaced wheels allowing it to straddle the crossbeams on which the rail moves.

It should be noted that this vehicle does not exert any tractive force on the rail: the force exerted on the rail to move it does not go through the wheels of the vehicle, which thus does not deteriorate the platform.

Advantageously, the method may include the following steps:

-   -   fastening rolling means on the crossbeams of the track under         construction,     -   moving said rail on said rolling means.

It is advantageous to reduce the friction of the rail on the crossbeams on which it is moved. To that end, rolling means will have been fixed beforehand, for example support frames bearing rollers, on some of the crossbeams. These support frames will be fastened at a distance from each other that allows the rail to move freely without rubbing on the crossbeams. The movement of the rail on said crossbeams is thus facilitated.

Advantageously, the method may include the subsequent step of repositioning the rails of the track under construction at their final location on the crossbeams.

Once the two rails of the first track are removed from the train and placed on the crossbeams, they are repositioned in their final location on the crossbeams using known vehicles and a known method. The rails of the second track portion, which have just been placed, must still be assembled to the rails of the first portion, already placed. The train can then progress on that second track portion without waiting for ballasting.

The invention also proposes a method for building a first and second railway track, said first track being built using the method described above, the construction of the second track including the following step:

-   -   placing, on a platform of said second track, at least one rail         substantially parallel to the direction of said first track so         as to build a second track portion parallel to the first track,         said at least one rail being placed from a train for storing and         placing rails traveling on said first track.

Once the first track is built using the previous method, the train can advance on that track and place the rails of the second track that is parallel thereto.

Advantageously, the method may include the following steps:

-   -   advancing the train for storing and placing rails on said first         track, and     -   placing, on the platform of the second track, at least one rail         near the location provided for the second rail by sliding said         rail out of the rail storage and placement train in a direction         toward the rear of the train and slanted relative to the axis of         the train.

When the train advances on the first track, the rails are removed from the storage cars toward the rear of the train and slanted, i.e., in the axis of the storage cars and with a lateral component. They are guided toward the crossbeams of the second track, to be placed near those crossbeams.

Advantageously, the method may include a step consisting of placing, on the platform, crossbeams in their substantially final location in said second track.

As for the construction of the first track, the final crossbeams of the second track are placed at their final location, subject to adjustments, before the placement of the rails, which is also a significant advantage of the method.

Advantageously, the rails of the second track may be placed on either side of said crossbeams of the second track.

The rails are placed on either side of the crossbeams to be able to be repositioned at a later time on those crossbeams, but they may be placed on the same side of the crossbeams.

When they are removed from the rail storage and placement train by sliding, the rails can be laterally guided to offset them toward the second track, since the train then travels on the first track. The train is equipped to that end with guiding means that will be described below. To that end, the elasticity of the continuous welded rails that are being placed is used.

The method may then include a step consisting of repositioning the rails in their final location on the crossbeams of the second track by using known vehicles and a known method.

The invention also relates to a method for building a first and second railway track in which it is possible to alternatively build a first track portion, then a second track portion, using a same rail storage and placement train progressing on an already-built first track portion.

In the method according to the invention, a first track portion, then a second track portion are alternatively built, using the same rail storage and placement train that advances on the first track under construction, and no longer in two separate operations. This method makes it possible to place a greater length of track per day.

The invention also relates to a rail storage and placement train that may include means, in its front end, for removing, from the rail storage cars and in the axis of and in front of said train, at least one first rail in order to build a track portion.

The train traditionally includes rail storage cars and one or more locomotives. At its front end, the train includes means for grasping and removing the rail from the storage cars in the extension of the train. These means therefore make it possible to “push” a rail to the front of the train when the train is stopped. Advantageously, the means for removing at least one first rail can include at least two pressure rollers suitable for pressing said first rail between two opposite faces and driving it by rotating said rollers.

At the front end of the train, the rail is grasped by pressure rollers that exert sufficient pressure on the rail to remove it from the storage cars by sliding the rail on the storage racks.

Advantageously, the train may also be extended, at its front end, by a support for said first rail including an inclined plane, so as to guide said first rail from the storage cars toward the upper face of the crossbeams on which it is placed.

The support is for example a mechanically welded structure including an inclined upper face, the upper part being at the storage racks of the rails and the lower part slightly above the upper face of the crossbeams. This structure makes it possible to guide the rail toward the upper face of the crossbeams while respecting standards related to the rail curvature in a vertical plane.

The structure may be equipped with wheels to allow it to be pushed by the train on the track under construction.

Advantageously, the rail storage and placement train may also include, at its rear end, means for transversely guiding least one second rail removed from said rail storage cars, so as to guide said second rail toward the location planned for a second track.

At its rear end, the train typically includes the locomotive(s) for propelling the train and stake cars that includes means for guiding the rails for their removal at a slant.

Advantageously, the transverse guide means may include at least one arm fixed to said rail storage and placement train and laterally overhanging said train.

The function of these arms is to guide the rails removed from the train at a slant transversely and toward the ground. They make it possible to respect the standards relative to rail curvature in the vertical and horizontal planes.

Advantageously, at least one arm may include a leg equipped with tired wheels, so as to roll on the platform as the train advances.

Embodiments and alternatives will be described below, as non-limiting examples, in reference to the appended drawings, in which:

FIGS. 1A, 1B and 1C show a crossbeam placement worksite in elevation, top view, and perspective view, respectively,

FIGS. 2A and 2B show a worksite for placing rails on a first track in elevation and top view, respectively, and an enlarged perspective view of part of that worksite,

FIGS. 2C and 2D show, in perspective view, enlarged views of the rail placement worksite on the first track,

FIGS. 3A and 3B show a rail placement worksite on the second track in top view and perspective view, respectively,

FIG. 3C shows an enlarged perspective view of a portion of a placement worksite for a second track,

FIG. 4 diagrammatically shows the alternative placement sequence for the rails of two tracks according to the method.

The method for building a new railway line, for example a TGV line, according to the invention includes three major steps:

-   -   placing crossbeams for the two tracks, using construction         vehicles,     -   placing rails for the first track, using the train that advances         on that first track,     -   placing rails for the second track, using the same train         traveling on the first track.

In the first major step, the first phase consists of forming stores 10 of crossbeams on the platform 5 and along the two tracks V1 and V2. These stores are formed by construction vehicles that access the platform 5 using access roads, for example side access roads 4 already existing or created for the purposes of the worksite. These stores 10 are characterized by their spacing D along the tracks and the quantity of crossbeams they contain. Knowing that the crossbeams, once placed, are 60 cm apart, a store provided to build a track with length D must include N=D/0.6 crossbeams. In this way, the vehicle that then places the crossbeams does not need to resupply between two stores.

In the stores 10, the crossbeams are assembled and stacked so as to be able to be taken up easily by a suitable spreader. The second phase consists of placing, on the platform, two parallel ballast layers 11 and 12 approximately 5 to 8 cm thick, in the form of strips following the future rail path. The purpose of these ballast layers is to procure a foundation for the single-piece reinforced concrete crossbeams (RCC) without any unevenness; they are arranged so as to form two foundations each representing approximately ⅓ of the length of the crossbeams starting from each end. These ballast layers are produced by a construction truck (not shown).

The first and second phases can be inverted or concomitant. During the first or second phase, the median axis of the future track is embodied by a colored line 13 that will form a guide for placing the crossbeams.

FIGS. 1A to 1C illustrate the third phase of the placement step of the crossbeams. It involves a traditional mechanical digger 20 equipped with a spreader 21 at the end of its articulated arm. This mechanical digger is hitched to a conveyor 30 mounted on a road trailer. The mechanical digger 20 picks up the crossbeams from the stores 10 using its spreader 21 and places them at one end of the conveyor 30. A crossbeam placement vehicle 40, called “layer,” mounted on tires 41, is hitched to the other end of the conveyor 30. This placement vehicle picks up the crossbeams from the conveyor and places them while respecting the sleeper spacing, i.e., their distance from each other, and the squaring, i.e., their orientation. An indexing device (not shown) secured to the placement vehicle 40 continuously monitors said sleeper spacing. The mechanical digger 20, conveyor 30 and placement vehicle 40 assembly travels along the future track by using the color line 13 as a reference.

The result of this first major step is a placement of final crossbeams of the two tracks V1 and V2 in their final location using the vehicles 20, 30, 40, which are all road vehicles, i.e., without the participation of a train.

FIGS. 2A to 2D illustrate the second major step of the method according to the invention. It involves a rail storage and placement train 50 and a guiding construction vehicle 60. This train 50 includes, from it is front end:

-   -   a longitudinal removal car 52,     -   rail storage cars 51,     -   cars for removing rails at a slant 53,     -   one or two locomotives L1, L2.

The train and the placement worksite progress in the direction illustrated by arrow F1 on the first track V1 under construction. It travels on the rails R11 and R21 of a track portion that is already laid. The front end of the train 50 is defined as that facing the direction of the track to be built.

The rails to be placed are “continuous welded rails” (CWR) measuring 400 m that cannot be manipulated by traditional vehicles and that are stored on the racks of the storage cars 51.

The longitudinal removal car 52 is at the head of the train; it is preceded by a mechanically welded structure 54 mounted on hoop wheels, which forms a ramp 55 for the rails during removal. This car 52 includes pressure rollers (not shown) that are adapted to grasp a rail R12 that will constitute part of the first track V1 and, owing to sufficient pressure exerted on two opposite faces of the rail, “push” it outside the car 52 in the axis of the train and in front of it, consequently in the extension of the first track portion that is already built. The placement of the rails outside their storage area may be done using a cable provided with a rail clamp and a winch.

Owing to its elasticity, the rail R12 joins the level of the upper face of the crossbeams by sliding on the ramp 55 of the structure 54. A guiding vehicle 60 grasps the front end of the rail R12 and guides it while advancing in the direction of the track to be built. To reduce the friction of the rails and the crossbeams, roller support frames (not shown) have previously been clipped on certain crossbeams, outside the final location of the rails, the distance separating them being sufficient to allow the rail to move freely without rubbing the crossbeams. The guiding vehicle 60 has two particularities: on the one hand, the arm 61 is rotatably mounted on the chassis so as to be able to grasp and guide each of the rails, given their spacing, and on the other hand, the wheels 62 are over-spaced to allow them to straddle the crossbeams.

In this second major step, the storage and placement train 50 is immobile on the first track portion V1 that has already been built. The operators begin by placing the roller support frames on the crossbeams, the rail R12 is pushed outside the train 50, slides on the ramp 55, then rolls on the support frames provided with rollers installed on the crossbeams, at the same time as it is guided by the guide vehicle 60; the second rail R22 is in turn pushed outside the train and guided. When the two rails R12, R22 are completely removed from the train 50 and placed on the crossbeams, a traditional repositioning vehicle (not shown) intervenes to place the rails at their final location on the crossbeams (repositioning operation). Once the rails are in their final location, the operators recover the roller support frames and store them in boxes 63 provided to that end on the guide vehicle 60. The rails R12, R22 are then fixed to the crossbeams and assembled to the corresponding rails of the track portion V1 that have already been built. An additional length of the first track V1 has therefore been built corresponding to the length of a CWR, on which the train 50 can advance.

In one improved alternative, the removal car 52 positions two sets of pressure rollers allowing it to move the two rails R12 and R22 simultaneously, and the arm 61 of the guide vehicle 60 includes a spreader allowing it to guide the two rails R12 and R22 simultaneously.

FIGS. 3A to 3C illustrate a third major step of the method according to the invention. The rails R31 and R41 of this second track are already laid, and in this step, the train 50 simultaneously places the rails R32 and R42 of the second track V2 while advancing on the first track V1.

At its rear end, the train 50 includes four flat cars 53 provided with arms 56 and 57 overhanging in the direction of the future track V2. The rails R32 and

R42 are removed from the train 50 at a slant toward the rear of the train; the purpose of these arms is to guide them laterally outside the train 50 toward platform 5 by playing on their elasticity. To that end, they include roller openings 59 inside which the rails slide. The arms 56 are cantilevered on the cars 53, the arms 57, called “bicycles,” are provided with tired wheels 58 to roll on the platform 5.

To remove the rails from their storage, a sling is passed into the roller openings, then the train withdraws enough to expose the previous unloading area. The sling is maintained on the rails using rail clamps. Between two rails unloaded end to end, a short sling provided with two rail clamps can make it possible to secure them.

The rails R32 and R42 are placed on either side of the crossbeams of the second track V2, but they may be placed on the same side. Once the placement is complete, a traditional vehicle intervenes to reposition them in their final location on the crossbeams. They are then fixed to the crossbeams and assembled to the rails R31 and R41 that have already been placed. This repositioning and assembly phase may take place at a later time, since the work train does not need the second track V2 immediately. It may for example occur during concurrent operation time, while the train 50 has returned to the staging ground to obtain rails. Placing the rails of the second track directly on the crossbeams in their final location may also be considered.

As illustrated in FIG. 4, the method is repeated to place the following rails R13 and R23 of the first track V1, then the rails R33 and R43 of the second track V2. The rails of the first track V1 and the second track V2 are placed longitudinally offset from the length of the storage and placement train.

The method is of course applicable to the construction of a first single track. 

1. A method for building a railway track (V1, V2) on a platform (5), characterized in that the final crossbeams are placed in their substantially final location and essentially by road vehicles (20, 30, 40).
 2. The method for building a railway track according to claim 1, characterized in that it includes the following step: embodying the median axis of the future track by a colored line (13) so as to form a guide for the placement of the crossbeams.
 3. The method for building a railway track according to claim 1, characterized in that it also includes the following steps: forming stores (10) of crossbeams on the platform (5) and along at least one track to be built (V1, V2) using road vehicles.
 4. The method for building a railway track according to claim 1, characterized in that it also includes the following step: placing on the platform (5), by road vehicle, two longitudinal layers of ballast (11, 12), in the form of strips parallel to the future railway track.
 5. The method for building a railway track according to claim 3, characterized in that it also includes the following step: picking up the crossbeams from said stores (10) by a construction vehicle (20) and placing them at one end of a conveyor (30) mounted on a road trailer.
 6. The method for building a railway track according to claim 5, characterized in that it also includes the following step: picking up and placing said crossbeams in their substantially final location while respecting the sleeper spacing and the squaring by using a crossbeam placement vehicle (40) mounted on tires hitched to the other end of said conveyor (30).
 7. The method for building a railway track according to claim 6, characterized in that an indexing device secured to said placement vehicle (40) continuously monitors said sleeper spacing.
 8. The method for building a railway track according to claim 1, characterized in that said road vehicles (20, 30, 40) access the platform of the track under construction using side access roads (4) already existing or created for the purposes of the worksite.
 9. The method for building a railway track according to claim 6, characterized in that said conveyor (30) and said crossbeam placement vehicle (40) are hitched to the construction vehicle (20), which therefore ensures the progression of the placement work.
 10. The method for building a railway track according to claim 5, characterized in that said construction vehicle is a mechanical digger (20) provided with an articulated arm and a spreader (21).
 11. The method for building a railway track according to claim 3, characterized in that in the stores (10), the crossbeams are assembled and stacked so as to be able to be taken up easily by a suitable spreader (21).
 12. The method for building a railway track according to claim 3, characterized in that a store provided to build a track with length D include N=D/0.6 crossbeams, such that the crossbeam-placing vehicle (40) does not need to resupply between two stores.
 13. A method for building a railway track (V1) on a platform (5), the crossbeams having been placed by a method according to claim 1, characterized in that it includes the following steps: removing at least one rail (R12) in the axis of a rail storage and placement train (50) and in front of it, said train (50) being stopped on the first already-built portion of said track under construction (V1), using removal means secured to said train, longitudinally moving at least one rail (R12) at least indirectly on the crossbeams of said track under construction, so as to build a second portion of said track (V1) in the extension of the first portion.
 14. The method according to claim 13, characterized in that the step consisting of moving said rail (R12) on said crosspieces of the track under construction includes: guiding said rail by a front end.
 15. The method according to claim 13, characterized in that it includes the following steps: fastening rolling means on the crossbeams of the track under construction (V1), moving said rail (R12) on said rolling means.
 16. The method according to claim 15, characterized in that it includes the subsequent step of: repositioning the rails (R12) of the track under construction (V1) at their final location on the crossbeams.
 17. A method for building a second railway track (V2) on a platform (5), said first track (V1) already having been built and the crossbeams of the second track having been placed using a method according to claim 1, characterized in that the construction of the second track (V2) includes the following step: placing, on a platform of said second track, at least one rail (R32, R42) substantially parallel to the direction of said first track (V1) so as to build a second track portion (V2) parallel to the first track, said at least one rail (R32, R42) being placed from a train for storing and placing rails (50) traveling on said first track (V1).
 18. The method according to claim 17, characterized in that it includes the following step: advancing the train for storing and placing rails (50) on said first track (V1), and placing, on the platform of the second track, at least one rail (R32, R42) near the location provided for the second rail (V2) by sliding said rail out of the rail storage and placement train (50) in a direction toward the rear of the train and slanted relative to the axis of the train (50).
 19. The method according to claim 18, characterized in that the step of sliding said rail outside the rail storage and placement train (50) includes the following step: laterally guiding said rail to offset it toward the location provided for the second track (V2).
 20. The method according to claim 17, characterized in that the rails (R32, R42) of the second track (V2) are placed on either side of said crossbeams of the second track.
 21. The method according to claim 20, characterized in that it includes the subsequent step consisting of: repositioning the rails (R32, R42) of the second track in their final location on the crossbeams.
 22. The method according to claim 17, characterized in that the rails (R32, R42) of the second track (V2) are placed on the crossbeams in their final location.
 23. A method for building a first (V1) and second (V2) railway track, characterized in that a first track portion (V1), then a second track portion (V2) using the method according to claim 17, are alternatively built, using the same rail storage and placement train (50) that advances on the first track (V1) under construction.
 24. A rail storage and placement train (50), characterized in that it includes means, at its front end, for removing at least one first rail (R12) in the axis of and in front of said rail storage and placement train (50), so as to build a portion of a track (V1).
 25. The rail storage and placement train (50) according to claim 24, characterized in that the means for removing at least one first rail (R12) include at least two pressure rollers suitable for pressing said first rail between two opposite faces and driving it by rotating said rollers.
 26. The rail storage and placement train according to claim 24, characterized in that it is also extended, at its front end, by a support (54) for said first rail including an inclined plane (55), so as to guide said first rail (R12) from the storage cars toward the upper face of the crossbeams on which it is placed.
 27. The rail storage and placement train according to claim 24, characterized in that it also includes, at its rear end, means for transversely guiding least one second rail (R32, R42) removed from said rail storage cars (51), so as to guide said second rail toward the location planned for a second track (V2).
 28. The rail storage and placement train according to claim 27, characterized in that the transverse guide means may include at least one arm (56, 57) fixed to said rail storage and placement train (50) and laterally overhanging said train.
 29. The rail storage and placement train according to claim 28, characterized in that at least one arm (57) may include a leg equipped with tired wheels (58), so as to roll on the platform as the train advances. 